Fatal error: Uncaught Error: Class "HTMLPurifier_Strategy" not found in /srv/www/htdocs/moodle/lib/htmlpurifier/HTMLPurifier/Strategy/RemoveForeignElements.php:11 Stack trace: #0 {main} thrown in /srv/www/htdocs/moodle/lib/htmlpurifier/HTMLPurifier/Strategy/RemoveForeignElements.php on line 11